public static void removeItem(EntityPlayer player, ItemStack is, int amount) {
	if(is == null)
		return;

	IInventory inv = player.inventory;

	for(int i = 0; i < inv.getSizeInventory(); i++) {
		if(inv.getStackInSlot(i) != null) {
			ItemStack stack = (ItemStack) inv.getStackInSlot(i);
			if(is.stackSize == 0)
				break;

			if(stack.stackSize == 0)
				inv.removeStackFromSlot(i);

			int mod = Math.min(is.stackSize, stack.stackSize);
			is.stackSize -= mod;
			stack.stackSize -= mod;
		}
	}
}